Wireless communication systems are well known in the art. Communications standards are developed in order to provide global connectivity for wireless systems and to achieve performance goals in terms of, for example, throughput, latency and coverage. One current standard in widespread use, called Universal Mobile Telecommunications Systems (UMTS), was developed as part of Third Generation (3G) Radio Systems, and is maintained by the Third Generation Partnership Project (3GPP).
FIG. 1 illustrates a conventional packet-optimized radio access network, in this case a UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN has one or more radio network controllers (RNCs) 104 and base stations 102, referred to as Node-Bs by 3GPP, which collectively provide for the geographic coverage for wireless communications with WTRUs 100, referred to as user equipments (UEs) by 3GPP. The geographic coverage area of a Node-B 102 is referred to as a cell. The UTRAN is connected to a core network (CN) 106.
An objective of the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA) program and the UMTS Terrestrial Radio Access Network (UTRAN) program of the Third Generation Partnership Project (3GPP) is to develop a packet-optimized radio access network with high data rates, low-latency, and improved system capacity and coverage. To achieve these goals, an evolution of the radio interface as well as the radio network architecture should be considered. For example, instead of using code division multiple access (CDMA), currently used in 3GPP, Orthogonal Frequency Division Multiple Access (OFDMA) and FDMA are proposed air interface technologies to be used in the downlink and uplink transmissions, respectively. Another proposed change is to apply an all packet switched service in the long term evolution (LTE) project. This means voice calls will be made on a packet switched basis.
Sequence hopping (SH) of reference symbols (RS) for the physical uplink control channel (PUCCH) and the physical uplink shared channel (PUSCH) may be utilized in such packet-optimized radio access networks. For example, one bit in the dynamic broadcast channel (D-BCH) may be used to indicate whether SH is enabled for PUCCH RS, an acknowledge/negative- (or non-) acknowledge (ACK/NACK) signal, or a channel quality index (CQI). The selection may apply to both PUCCH and PUSCH, but not necessarily the same hopping pattern.
If hopping is disabled, the sequence group may be explicitly indicated. Five (5) bits are typically used to indicate 30 groups. If hopping is enabled, the signaling of the hopping pattern is yet to be determined (D-BCH or cell-specific). As the SH patterns used by different cells may be different, it is desirable to have a signaling method and apparatus for an SH pattern changes, such as for reference symbols, ACK/NACK signals, or CQI, that may occur during handover from a current cell to a target cell.